HONG KONG, April 6 (Xinhua) -- China on Sunday voiced objection to U.S. Vice President Joe Biden's meeting with two Hong Kong former legislators and called on the United States to refrain from interfering in Hong Kong's affairs.

One spokesman of office of the Commissioner of the Foreign Ministry of China in Hong Kong said Hong Kong's affairs are China' s internal affairs. China objects firmly to any country's interference in China's internal affairs in any form.

The spokesman made the comments when asked to respond to Biden' s meeting with two Hong Kong activists on Friday.

White House said Biden stopped by talks with former Hong Kong Legislative Council member Lee Chu-ming and former Chief Secretary Chan Fang On-sang. They are on a two-week visit to North America.

The two activists expressed concerns over freedom of the press in Hong Kong after a recent knife attack on Kevin Lau, a former editor of Ming Pao newspaper. They also expressed worries that freedom and other core values of Hong Kong are under threat.

The spokesman dismissed such notions.

"Over the past 17 years since Hong Kong's return, the region has seen the successful implementation of the 'one country, two systems' framework, which contributed to Hong Kong's great socioeconomic and democratic development. As a result, the people in Hong Kong are enjoying unprecedented democratic rights and freedom, which has won international acclaim," said the spokesperson.

The spokesman urged the United States to "proceed discreetly" regarding Hong Kong's affairs to avoid damage to China-U.S. ties as Hong Kong is currently at a critical time of political reform.